Related Tags:

OAKLAND (CBS) – In the steel rafters of the old Bay Bridge, a flock of fowl you may never have noticed has built its home; but those homes will have to come down as the old section of roadway is replaced.

The colony of cormorants has constructed roughly 400 nests hidden along a mile-long stretch of the eastern span.

“They like it. They like the Bay Bridge. They’ve been there for at least 20 years, since the 1980′s,”said Stefan Galvez-Abadia District Branch Chief of the California Department of Transportation.

Caltrans saw the problem coming, and has spent about a half a million dollars building small platforms into the new span. They are being called cormorant condos, designed as a place where the birds can make a new home. But birds of a feather are apparently picky about where they flock together.

“We haven’t observed any birds moving over yet,” said Galvez-Abadia.

Last year, Caltrans started wooing the birds, first with fake nets, then with decoys.

“We did not have any birds moving over,” said Lauren Bingham, the Caltrans biologist heading up the relocation project. “We had to get creative.”

Caltrans has now installed speakers beneath the bridge to blast the mating call of the cormorant, hoping that will convince them to make the switch.

The installation is going into place just in time for the cormorant mating season, which runs from March to August.

“We have put in the time and the research to design something that should potentially work, but it may not, because they’re birds and you can’t predict exactly what they’re going to do,” said Bingham.

Caltrans said time is on their side. The nesting section of the old bridge isn’t scheduled for demolition until 2015.